The overall goal of this application is to address a national priority in cancer control research by developing and conducting a highly innovative patient navigation program from the point of abnormal screening test to treatment for breast, colorectal and prostate cancers. The major venue for this program of research will be the Denver Health Medical Center (DH), which is the single largest "safety net" health care system linked to a major metropolitan area in the Rocky Mountain Region. DH serves a large number of minority (75%) and underserved patients (almost half without insurance). Unique features of this research are: (1) testing for efficacy and cost-effectiveness a comprehensive patient navigator program that will extend an existing and exemplary community lay health worker demonstration project at DH (Community Voices); (2) combining this resource with a well-established telephone counseling service to specifically address patient-centered psychosocial barriers; and (3) integrating these components into a comprehensive patient navigator program within the context of the healthcare provider institution. The following specific aims will guide the evaluation of this program: (1) to reduce the time between an abnormal screening test for breast, colorectal and prostate cancers to a positive or negative pathologic diagnosis; (2) to reduce the time from a positive pathologic diagnosis of breast, colorectal or prostate cancers to the start of therapy; (3) to increase the proportion of these patients adhering to recommendations for care, including completion of additional diagnostic tests, consultation appointments, and completion of treatment; (4) to improve patient reported outcomes of medical self-efficacy, satisfaction with care and distress related to cancer diagnosis in a sample of individuals with a negative pathologic diagnosis and among all individuals with a positive pathologic diagnosis; and (5) to examine the cost-effectiveness and return on investment of patient navigation. Ultimately we will demonstrate the efficacy and assess the financial impact associated with the implementation of a comprehensive navigation program designed to address disparities in cancer-related outcomes among the poor and underserved